Decreasing feature sizes and increasing package densities are making thermal issues important in integrated circuit related products, particularly high power products such as server products. The total thermal design power is increasing with respect to generation which demands that cross-plane heat removal be improved. Still further, the emergence of multi-chip packages (MCPs) in, for example, high-power servers where, for example, multi-chip dynamic random access memory (MC-DRAM) stacked packages currently generate approximately nine watts to 10 watts of power and come coated with die backside film polymeric layers that present a high thermal resistance that is difficult to compensate for with traditional air cooling.
Many high-power central processing unit (CPU) products use an integrated heat spreader (IHS) as a lid over the die (e.g., a silicon die or dies). Onto this lid mounts a thermal solution, such as a passive heat sink, a heat sink/fan combination or liquid cooling solution. Limitations of these configurations include a relatively large stack-up height and multiple thermal interfaces where thermal interface material (TIM) must be applied. Thermal performance of TIM materials have been optimized yet a need still remains to improve the thermal management of high-power microprocessors.